Featured Research

Number Of Cerebral Cells At Embryonic Development Stage Controlled By Newly Discovered Mechanism

Date:

February 23, 2009

Source:

Instituto de Investigaciones Biomédicas Alberto Sols

Summary:

Researchers have discovered that a protein present in the nucleus of progenitor cells of the embryonic central nervous system forms part of the genetic mechanisms through which these cells transform into neurons and astrocytes, the two cell types that constitute the majority of the adult brain.

Share This

A group of researchers of the Instituto de Investigaciones Biomédicas Alberto Sols (a mixed centre of the Consejo Superior de Investigaciones Científicas and the Universidad Autónoma de Madrid) have discovered the participation of a protein denoted DREAM in the activation of genes that are necessary for the progenitor cells of embryonic brains to differentiate themselves into astrocytes.

Related Articles

The study, published in The Journal of Neuroscience, was directed by Dr. Mario Vallejo, and constitutes part of the doctoral thesis of Beatriz Cebolla and Antonio Fernández-Pérez, co-authors of the article.

Studies previously conducted in Dr. Vallejo's laboratory put forth that progenitor cells of the embryonic cerebral cortex are capable of responding to particular extracellular signals by increasing the levels of a second intracellular messenger called cyclic AMP. This second messenger is capable of activating mechanisms that alter the genetic program of progenitor cells and induce them to differentiate into astrocytes.

Working in collaboration with Dr. Alfonso Araque and Dr. Gertrudis Perea of the Instituto Cajal de Madrid (Consejo Superior de Investigaciones Científicas), also co-authors of the study, the researchers determined that the cyclic AMP produced activates the entry of calcium from the extracellular environment into the cell, and that calcium is responsible for the genetic effects of cyclic AMP. Among others, this discovery suggested that a possible mechanism by which calcium could mediate cyclic AMP effects over the expression of genes crucial for the differentiation of astrocytes could be through the activation of the DREAM protein. It is already well known that DREAM is a transcription factor, which means that it is a protein capable of directly regulating the expression of certain genes, and that its activity is regulated by calcium.

The research team discovered that DREAM regulates the activation of essential genes for the differentiation of astrocytes. When DREAM is not present, progenitor cells can not differentiate into astrocytes after being brought in contact with signals that act through the production of cyclic AMP. Nevertheless, these cells do not lose their differentiation capability, since they can transform into astrocytes as a response to different signals that do not require the production of this second messenger.

The research group managed by Dr. Vallejo observed that during the postnatal period, a period during which most astrocytes are generated, the brains of mice lacking DREAM contained an abnormally low number of these cells. Surprisingly, while gathering this data, the researchers noticed that the brains of mice lacking DREAM contained an abnormally high number of neurons.

Taking into consideration that during the development of the brain, the neural progenitors produce neurons before producing astrocytes, these results indicate that DREAM takes part in the mechanism that blocks the production of neurons while activating the production of astrocytes. In the brains of mice lacking DREAM, compensation mechanisms take place that ensure that the adult animals would produce an abnormally high number of astrocytes during their lifetime, reinforcing the theory that the relation between the number of neurons and astrocytes has a great functional importance. Therefore, the lack of DREAM produces brains with a higher number of cells.

The authors of the study have emphasized the importance of the cyclic AMP-calcium-DREAM system in the mechanisms responsible for the production of astrocytes and controlling the number of neurons and astrocytes produced from neuronal progenitors during the development of the brain.

Featured Research

Mar. 31, 2015 — Researchers have illuminated an important distinction between mice and humans: how human livers heal. The difference centers on a protein called PPAR alpha which activates liver ... full story

Mar. 31, 2015 — Researchers have recorded the first direct observations of the micro-scale mechanisms behind the ability of skin to resist tearing. The results could be applied to the improvement of artificial skin, ... full story

Mar. 31, 2015 — Fewer than half of the physicians trained in the United States in 2013 received formal education or training on the subject of exercise, according to new research. "There are immense medical benefits ... full story

Mar. 31, 2015 — Memory and as well as connections between brain cells were restored in mice with a model of Alzheimer's given an experimental cancer drug, researchers report. "With this treatment, cells under ... full story

Mar. 31, 2015 — Increasing state alcohol taxes could prevent thousands of deaths a year from car crashes, say researchers, who found alcohol-related motor vehicle crashes decreased after taxes on beer, wine and ... full story

Mar. 31, 2015 — Alcoholism takes a toll on every aspect of a person's life, including skin problems. Now, a new research report helps explain why this happens and what might be done to address it. "The clinical ... full story

Mar. 31, 2015 — A new population of 'memory' immune cells has been discovered by scientists, throwing light on what the body does when it sees a microbe for the second time. This insight, and others like it, will ... full story

Mar. 31, 2015 — Coronary heart disease and stroke, two of the leading causes of death in the United States, are diseases associated with heightened platelet reactivity. A new study in humans suggests an underlying ... full story

Mar. 31, 2015 — A new study had researchers seeking answers to why the therapeutic benefit afforded by SSRIs was so limited in children and teenagers. If researchers can uncover the biological mechanisms preventing ... full story

Featured Videos

Solitair Device Aims to Takes Guesswork out of Sun Safety

Reuters - Innovations Video Online (Mar. 31, 2015) — The Solitair device aims to take the confusion out of how much sunlight we should expose our skin to. Small enough to be worn as a tie or hair clip, it monitors the user&apos;s sun exposure by taking into account their skin pigment, location and schedule. Matthew Stock reports.
Video provided by Reuters

Soda, Salt and Sugar: The Next Generation of Taxes

Washington Post (Mar. 30, 2015) — Denisa Livingston, a health advocate for the Diné Community Advocacy Alliance, and the Post&apos;s Abby Phillip discuss efforts around the country to make unhealthy food choices hurt your wallet as much as your waistline.
Video provided by Washington Post

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015) — Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17
Video provided by AFP

Related Stories

Mar. 11, 2015 — An important step in the area of cell therapy has been taken by scientists: repairing the cerebral cortex of the adult mouse using a graft of cortical neurons derived from embryonic stem cells. These ... full story

July 17, 2014 — Throughout our lives, our brains adapt to what we learn and memorize. The brain is indeed made up of complex networks of neurons and synapses that are constantly re-configured. However, in order for ... full story

Sep. 10, 2012 — Researchers report that a cell-to-cell communication network known as the Wnt signaling pathway plays an important role in both the production and specialization of nerve cell precursors in the ... full story

May 12, 2011 — Neural stem cells can do a lot, but not everything. For example, brain and spinal cord cells are not usually generated by neural stem cells of the peripheral nervous system, and it is not possible to ... full story

May 25, 2010 — New insight into what stem cells are and how they behave could help scientists to grow cells that form different tissues. A new study has shown that embryonic stem cells consist of cells that switch ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.